A substance called Miracle Mineral Solution has developed a cult following among a subset of the anti-vaxxer community, where it is believed to be a cure for everything from diabetes to AIDS.

Whether you have AIDS, malaria, cancer, or autism, there is a product sold on the internet that claims it can cure you. That product, called Miracle Mineral Solution (MMS), sounds a lot like other pseudoscientific remedies—but unlike many suspect forms of new age medicine that are scientifically unproven but benign, MMS can actively harm you in serious ways. That's because it's a solution of 28 percent sodium chlorite which, when mixed with citric acid as instructed, forms chlorine dioxide (ClO2), a potent form of bleach used in industrial pulp and textile bleaching.

Obviously, this is not exactly something you want to put in your body. And yet some parents are giving this dangerous substance to their children, both orally and through enemas, in the belief that it will cure their child of autism.

The FDA has been aware of MMS for some time; in 2010 it issued a warning that the product turns into "a potent bleach" that "can cause nausea, vomiting, diarrhea, and symptoms of severe dehydration" if ingested. There are reports of at least one possible death from MMS use, and in January children were removed from a home in Arkansas on the suspicion that parents were giving them the solution in some form. Media investigations have shown that the substance will quickly bleach cloth, leading one scientist to tell North Carolina's WFMY News that she would only use it to clean her shower.

Nevertheless, there are a number of people who are convinced that using Miracle Mineral Solution—also known as following the "CD Protocol" (CD stands for chlorine dioxide)—will cure whatever ails them. They believe that it works by clearing the body of mystery parasites known as "rope worms" and other pathogens that they believe cause autism (this theory, to be clear, is wholly unsupported by medical science). And it's not just autism. MMS is marketed as a classic cure-all, purported to treat everything from diabetes to malaria to Ebola to AIDS. There's even a pseudo-Wikipedia where you can look up which "protocol" to follow to cure any illness, whether the complaint is baldness or brain cancer.

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If this all sounds a little cultish, that's because it is. MMS was "discovered" by a man named Jim Humble, a former Scientologist who started his own church, called Genesis II, of which he is now the self-styled Archbishop. The church appears to be little more than a marketing organ for his alleged miracle cure, though it's worth noting that the site doesn't sell the actual wonder product it extolls, but offers a host of supplementary materials like a $199 "MMS Home Video Course" and information on expensive MMS seminars.

If Humble is the pater familias of this wolfpack of chicanery, a woman named Kerri Rivera seems to be its den mother. A bishop in Humble's church, Rivera is the author of a book titled Healing the Symptoms Known as Autism, in which she recommends giving autistic children "hourly doses" of chlorine dioxide and advocates chlorine dioxide enemas as a way to "kill pathogens in the brain."

Her website, CDAustism.org, is—like Humble's website—careful to state that it does not actually sell MMS. Instead it promotes the idea that it will cure autism, sells supporting materials like her book, and offers expensive Skype consultations on administering the "treatment" that cost over $100 per hour.

In other words, while stopping short of selling MMS (likely for legal reasons), Humble and Rivera instead advocate it as a lifestyle, thereby promoting the damaging idea that the complex neurological condition known as autism is essentially a gut problem that you can somehow power-wash out of your body by pouring industrial bleach into both ends. And their followers believe them. (Questions sent to Ms. Rivera were unanswered at the time of publication.)

MMS enthusiasts talk casually, like they're swapping recipes, about how many inches to insert the catheter into their child's rectum.

There's no way to accurately estimate how many people are doing this to themselves or their children. One of Humble's websites outlandishly states 20 million people have been served by MMS, while Rivera claims a more modest (but chillingly specific) 164 children have been cured from autism, a number based on unverified testimonials.

As their behavior comes under increasing legal scrutiny, MMS enthusiasts have become an elusive bunch, recently abandoning a Facebook page that boasted over 7,000 members and moving to a more anonymous message board hosted on CDAutism.org where they say, with no apparent irony, that they feel more "safe," since making an account is required here.

Yet it's in these threads, where those who have bought into the miracle cure share their stories and discuss dosing strategies, that the evidence against MMS/CD is most damning and most clear.

Going through these posts is like wading through a witches' brew of misinformation, pseudoscience, and paranoia. Here you can find parents speaking openly about the merits of drinking ocean water and performing parasitic cleanses timed to the cycles of the moon. MMS enthusiasts talk casually, like they're swapping recipes, about how many inches to insert the catheter into their child's rectum, how to force them into a chlorine dioxide bath, and how to use "tactics and tricks" to overcome resistance from children as young as two to receiving a bleach enema.

Most horrifyingly, these "tactics and tricks" even include using the child's own autism—i.e. a "love of routine"—against them.

Guided by largely anonymous moderators, users trade anecdotes in place of science, all while making health decisions that will affect their children in intimate ways, with unknown physical and psychological side effects. Meanwhile, the mods issue reassuring comments not to worry about things like reduced bowel function or "hundreds of small red objects" in a child's stool after enemas. They are convinced it's all part of the healing process.

Many MMS fans believe that vaccines result in parasites, which in turn cause autism.

There's a strong strain of anti-vaxx sentiment that runs through this subculture, since vaccines are viewed by many chlorine dioxide users as the initial source of their child's autism. Much of this is the result of the ongoing ripple effect of a discredited 1998 study that posited a possible connection between the MMR (measles, mumps, and rubella) vaccine and autism. Despite being debunked, the study continues to infect the public debate around vaccines, contributing to recent outbreaks of long-beaten diseases like measles.

Unlike other strains of anti-vaxxers, though, many MMS fans believe that vaccines result in parasites, which in turn cause autism. I asked Emily Willingham, a science writer who's written about MMS for Forbes and Thinking Person's Guide to Autism, if she could explain this logic.

"One of the tenets of the vaccines-cause-autism movement is that the vaccines contain toxins, that a 'leaky gut' is somehow involved, and that these vulnerabilities lead to parasitic infections, yeast overload, and a host of other weird, unrelated things that 'need' to be treated," Willingham wrote in an email.

Indeed MMS/CD enthusiasts are downright obsessed with parasites. On CDAutism.org and elsewhere they post stomach-churning photos of what they believe to be "rope worms" or other parasites passed by their children after oral or rectal doses of chlorine dioxide. (The evidence that rope worms even exist is extremely limited.)

I corresponded with a doctor in South Africa, Louise Lindenberg, who has tested three such stool samples, given to her by a parent who admitted to using chlorine dioxide on herself and her children. She found no evidence of said parasites. "The microbiology did not reveal any parasites or even eggs," Lindenberg wrote in an email. "Histology confirmed that it was a combination of mucus, plant material, enterococci (probiotic flora), and gut cells."

What she did find, however, was "abdominal discomfort, aggravated behavior, weight loss, low sodium levels, [and] iron deficiency" in her patients. To be clear, I asked for her opinion on MMS/CD. Lindberg, who is herself an autism expert, replied: "I feel that it is potentially very harmful and does not 'cure autism' in any way."

When there are alarming side effects from the enemas the solution is... more enemas.

According to Fiona O'Leary, an autism advocate and activist based in Ireland and a leading opponent of MMS/chlorine dioxide use, the issue is clear: "We need to stop with these quack treatments because they're dangerous, they're not authorized, they're not proven, and if anything they're proven to cause real harm."

O'Leary—the mother of two autistic children, and who is on the spectrum herself—has been involved in activism against MMS in Ireland since 2014. She has catalogued numerous instances of apparent abuse on MMS message boards and Facebook groups. In a lengthy conversation, O'Leary discussed her ongoing campaign against MMS and compared chlorine dioxide use to other discredited treatments for autism like chelation and shock therapy.

"It's like something from a Stephen King horror film," she said. "They're guinea pigs. They don't have a life. From the minute that they wake up in the morning they're dosed with the [chlorine dioxide], and they're dosed throughout the day. Parents are removing them from school because they're not allowed to dose in school and they're hiding from child protection authorities because they know what they're doing is wrong."

O'Leary's claims seem as incredible as they are horrifying, but indeed, parents who frequent the CDAutism forums openly swap tips on how to duck Child Protective Services, which have become aware of chlorine dioxide's use on children in some areas.

"It's so unbelievable that you have to pinch yourself. But it is happening. It's happening where I live," said O'Leary, who says she's been offered MMS in Ireland—in one case by a dentist.

If it defies belief, it certainly defies logic. Chlorine dioxide's fanatics are so wedded to their method that its core truth cannot be questioned. In fact, in their warped view, negative effects on the child like the alarming stools above are proof that the therapy is working and that more chlorine dioxide is needed to further purge the body.

When children are hyperactive or anxious—which is taken as evidence of autistic behavior—both advice on the CDAutism.org forums and in Rivera's book suggest "double dosing." In addition to irregular stools, parents report symptoms in their children such as nausea, diarrhea, and "pink urine"—things that seem clear to be a result of ingesting bleach, but are again taken as evidence of autism. The validity of the protocol itself is sacrosanct. And in this twisted world, when there are alarming side effects from the enemas the solution is... more enemas.

Here a concerned parent wonders why his son "writhes around in pain after each dose" but explains that he had to "ramp up the dose pretty quickly" to avoid unwanted "behaviors."

O'Leary has no sympathy for anyone giving their children chlorine dioxide and painted a bleak portrait of life in an MMS household, one that sifting though the CDautism.org forums at length only reinforced: a life of tightly restricted diets, constant oral dosing with chlorine dioxide, and regular, invasive, chlorine dioxide enemas. A life of pain.

"They're so far removed from what they're doing sometimes that you think that they shouldn't even have a dog. They're not fit to have children," said O'Leary.

There is no cure for autism, which is increasingly being seen as an example of neurodiversity rather than as a disease, and Willingham believes it's the notion that autism is a "horrific tragedy, a disease that 'steals' the real child away" that's caused some people to buy into dangerous, quack "therapies."

"Autism is a neurodevelopmental condition that traces to early fetal development. You can't bleach it away, and autistic people deserve respect and attention to their personhood," said Willingham.

There are positive signs that the Department of Justice is cracking down on distributors in the United States—in 2013, a major MMS supplier named Louis Daniel Smith was arrested on charges related to smuggling and mislabeling the substance. (The trial starts this month, and Smith's supporters have been crowdfunding his defense fund.) But MMS remains technically legal.

O'Leary fears that without further regulation, phony treatments like chlorine dioxide will become worse and more widespread. Jim Humble regularly posts chilling photos of visits to impoverished countries where chlorine dioxide is given to already suffering people as a supposed cure for malaria and AIDS, and in February announced plans to build a Genesis II church in Sierra Leone.

Though several countries, including Canada and Ireland, have issued health warnings O'Leary says she hopes that increased media attention will move the powers that be to take more concrete action.

"I just hope to God that the government picks up on it and actually look at this as a human rights violation," said O'Leary. "It's nothing less than that."